Manufacturing method of expanded mesh

ABSTRACT

In an expanded mesh of this invention, a latitude skeletal element composing a mesh has a length which is substantially not elongated from a state of a sheet-shaped material. For this reason, the expanded mesh is not bulged like a barrel. Namely, it is flat. Since a longitudinal skeletal element is inclined acutely relative to straight portions as compared with a conventional expanded mesh, the expanded mesh will become a grid with good current collecting efficiency when a lug of current collector plate is formed on an inclining direction side.

TECHNICAL FIELD

This invention relates to an expanded mesh and its manufacturing method,and further to a lead acid storage battery plate using the expandedmesh.

BACKGROUND ART

There are an after stretching system and a simultaneous opening systemin an expanding work method. The after stretching system is one in whichcut slits are first made in a sheet-shaped material and the cut slitsare then expanded, as disclosed for example in Published PatentApplication (KOKAI) No. 52-144745. The simultaneous opening system isone in which the cut slits are made in the sheet-shaped material and thecut slits are expanded simultaneously, and which is classified into aparallel cutter system and a right angle cutter system. The parallelcutter system is one which uses cutter lines comprising cutters arrangedstepwise and in parallel each other so as to give broken lines parallelwith a feed direction of the sheet-shaped material, as disclosed forexample in Published Patent Application (KOKAI) No. 53-79760. The rightangle cutter system is one in which one row of cutter lines arrangedright angle to the feed direction of the sheet-shaped material is movedvertically and the cutters are swung in an arranged direction on everypitch in order to put meshes into zigzag positions, as disclosed forexample in U.S. Pat. No. 3,310,438.

Generally, a grid for use in the lead acid storage battery plate has sofar been manufactured by casting or machining. However, a percentage ofmanufacture by machining providing a high productivity is increasing inrecent years, and a manufacturing method using expanding work ofsheet-shaped material made of lead alloy is prevailing now as a typicalmachining work. A grid which is formed from an expanded sheet-shapedmaterial made of copper alloy, attached by casting with a currentcollector plate having a lug, and coated with lead on its surfacethereafter, may be mentioned as a grid for use in a comparatively largelead acid storage battery plate.

However, the above-mentioned after stretching system has included such aproblem that a special expanding process has been required.

The parallel cutter system has included such a problem that a die-sethaving a very long cutter line has been required because a pitch ofcutter has had to be made 1.5 times as large as a pitch in cut lengthdirection of the sheet-shaped material and it had not been able toexpand the cut lines largely in spite of an expanding direction beingsame with a direction of height of reticulated portion. The right anglecutter system has included such a problem that it has not been able tocontinuously manufacture the expanded mesh having a non-expanded partand a reticulated portion and a high-speed production has beenimpossible because it has been required to swing the cutter line.

The expanded mesh obtained by the conventional method has included aproblem of poor current collecting efficiency because of an obtuseinclining angle of skeletal element composing the mesh relative to sideedges.

In the above conventional system, only a cutter merely making the cutslits can be used as a cutter for forming a mesh adjacent to thenon-expanded portion in order not to elongate the non-expanded portion.Therefore, the system has included such a problem that it has not beenable to form a large mesh in this part and to effectively utilize thesheet-shaped material.

In the grid for use in a comparatively large lead acid storage batteryplate, a current collector plate having a lug is formed separately andattached to the expanded mesh. In this way, a large expanded mesh ismanufactured by the right angle cutter system. For this reason, therehave been such problems that the expanded mesh has been corrugated overits entire circumference, a process for remedying the entirecircumference after installing another members on it has been requiredand troublesome, and the remedy work has been hard.

DISCLOSURE OF THE INVENTION

This invention is made in consideration of the above-mentioned problems,and objects of this invention are to provide a flat expanded mesh, toprovide a manufacturing method of expanded mesh enabling easy andprecise manufacture of such an expanded mesh by means of a simultaneousopening by using a small die-set, and further to provide a flat leadacid storage battery plate having a good current collecting efficiency.

This invention provides a sheet-shaped expanded mesh made of asheet-shaped material; characterized in that the expanded mesh comprisesa reticulated portion and straight portions composed of non-expandedportions formed at least on one-side, the reticulated portion has alarge number of meshes surrounded by longitudinal skeletal elementsinclining relative to the straight portions, latitude skeletal elementsapproximately parallel to the straight portions, and nodes of the bothskeletal elements, meshes not adjacent to the straight portions aresurrounded by a pair of approximately parallel latitude skeletalelements, a pair of approximately parallel longitudinal skeletalelements, and a pair of nodes opposing each other, meshes adjacent inlatitudinal direction have the longitudinal skeletal elements in common,the latitude skeletal element has a length which is substantially notelongated from a state of the sheet-shaped material, and thelongitudinal skeletal element has a length which is elongated from astate of the sheet-shaped material within a range of breaking limit.

The expanded mesh having the above-mentioned structure is not bulgedlike a barrel because the latitude skeletal element has the length whichis substantially not elongated from the state of the sheet-shapedmaterial. In other words, it is flat. Since the longitudinal skeletalelement is inclined acutely relative to the straight portion as comparedwith a conventional expanded mesh, it will become a grid with goodcurrent collecting efficiency when a lug of current collector plate isformed on an inclining direction side.

In the expanded mesh having the above structure, the node may beintegrated with the latitude skeletal element. According to thisstructure, the latitude skeletal element will become thick so that alatitudinal rigidity will be improved.

This invention provides a manufacturing method of sheet-shaped expandedmesh made of a sheet-shaped material; characterized in that the expandedmesh comprises a reticulated portion and straight portions composed ofnon-expanded portions formed at least on one-side, the reticulatedportion has a large number of meshes surrounded by longitudinal skeletalelements inclining relative to the straight portions, latitude skeletalelements approximately parallel to the straight portions, and nodes ofthe both skeletal elements, meshes not adjacent to the straight portionsare surrounded by a pair of approximately parallel latitude skeletalelements, a pair of approximately parallel longitudinal skeletalelements, and a pair of nodes opposing each other, meshes adjacent inlatitudinal direction have the longitudinal skeletal elements in common,a die-set is used which is equipped with at least one-row of dieinstalled in an inclining position relative to a feed direction of thesheet-shaped material and plural shearing cutters protruding at itsmiddle part and shearing with the die to shear the sheet-shaped materialinto broken-line-like shapes and opening it to form the reticulatedportion, and a direction of shearing motion relative to the die ofshearing cutter is set in a direction inclining to a thickness directionof the sheet-shaped material so as to include a pitch feed motion of thesheet-shaped material from its feed destination side to its feed originside.

According to the above method, it becomes possible to elongate thelongitudinal skeletal element only and not to elongate the latitudeskeletal element. Thereby, the flat expanded mesh can be obtained inspite of the non-expanded portion included.

In the above manufacturing method, the following structures may be used.

(1) The shearing cutter has at its tip end a tooth protruding at itscentral part. The tooth has at least a first tooth for shearing andforming the latitude skeletal element and a third tooth for shearing andforming the longitudinal skeletal element. The first tooth is inclinedby a first angle relative to a plane normal to the direction of shearingmotion of the cutter, the sheet-shaped material facing on the cutter isinclined by a second angle to a side opposite to the first toothrelative to a plane normal to the direction of shearing motion of thecutter, and the first angle is set to a value approximately equal to orsmaller than the second angle, the node is formed of a part, which islocated between teeth of adjoining cutters and does not shear thesheet-shaped material, by pitch feeding the sheet-shaped material at apitch smaller than or equal to a tooth width of the cutter.

In the above method, an inclining angle of a first tooth 71a relative toa horizontal plane X is β (first angle), an inclining angle of the wholecutter 7 relative to the horizontal plane X is α (second angle), and aninclining angle of a sheet-shaped material 10 relative to the horizontalplane X is α (second angle), as illustrated in FIG. 10. Therefore, in apart of the sheet-shaped material 10 immediately after being sheared bythe cutter 7, a triangle having sides a and b becomes approximately anisosceles triangle because α is roughly equal to β. In other words, alength of the side a is roughly equal to a length of the side b.Accordingly, a latitude skeletal element 52 is formed by only shearingthe sheet-shaped material 10 downward approximately as it is, and has alength substantially not elongated from a state of the sheet-shapedmaterial 10. Consequently, the obtained expanded mesh does not become amesh bulged like a barrel in latitudinal direction.

This invention provides a lead acid storage battery plate in which apaste-like active material is held in a grid having a sheet-shapedexpanded mesh made of a sheet-shaped material; characterized in that thegrid comprises a reticulated portion and straight portions composed ofnon-expanded portions formed on at least on one-side, the reticulatedportion has a large number of meshes surrounded by longitudinal skeletalelements inclining relative to the straight portions, latitude skeletalelements approximately parallel to the straight portions, and nodes ofthe both skeletal elements, meshes not adjacent to the straight portionsare surrounded by a pair of approximately parallel latitude skeletalelements, a pair of approximately parallel longitudinal skeletalelements, and a pair of nodes opposing each other, meshes adjacent inlatitudinal direction have the longitudinal skeletal elements in common,the latitude skeletal element has a length which is substantially notelongated from a state of the sheet-shaped material, the longitudinalskeletal element has a length which is elongated from a state of thesheet-shaped material within a range of breaking limit, and a luglocated on an elongated direction side of the longitudinal skeletalelement is formed on the straight portion of one-side.

The lead acid storage battery plate having the above-mentioned structureis not bulged like a barrel because the latitude skeletal element hasthe length which is substantially not elongated from the state of thesheet-shaped material. In other words, it is flat. Since the lug islocated on the elongated direction side of the longitudinal skeletalelement, a good current collecting efficiency will become obtainable.

This invention provides an another lead acid storage battery plate inwhich a paste-like active material is held in a grid having asheet-shaped expanded mesh made of a sheet-shaped material;characterized in that the grid comprises a reticulated portion andstraight portions composed of non-expanded portions formed on opposingtwo-sides, the reticulated portion has a large number of meshessurrounded by longitudinal skeletal elements inclining relative to thestraight portions, latitude skeletal elements approximately parallel tothe straight portions, and nodes of the both skeletal elements, meshesnot adjacent to the straight portions are surrounded by a pair ofapproximately parallel latitude skeletal elements, a pair ofapproximately parallel longitudinal skeletal elements, and a pair ofnodes opposing each other, meshes adjacent in latitudinal direction havethe longitudinal skeletal elements in common, the latitude skeletalelement has a length which is substantially not elongated from a stateof the sheet-shaped material, the longitudinal skeletal element has alength which is elongated from a state of the sheet-shaped materialwithin a range of breaking limit, and a current collector having a lugis fitted to one-side, other than the straight portion, stretching overboth ends of the straight portions located at both sides.

The lead acid storage battery plate having the above-mentioned structureis not bulged like a barrel because the latitude skeletal element hasthe length which is substantially not elongated from the state of thesheet-shaped material. In other words, it is flat. Since the latitudeskeletal element stretches toward the current collector, a good currentcollecting efficiency will become obtainable. Further, the side on whichthe straight portion is installed can hold the active material even ifanother members are not installed.

This invention provides a further another lead acid storage batteryplate in which a paste-like active material is held in a grid having asheet-shaped expanded mesh made of a sheet-shaped material;characterized in that the grid comprises a reticulated portion andstraight portions composed of non-expanded portions formed on opposingtwo-side, the reticulated portion has a large number of meshessurrounded by longitudinal skeletal elements inclining relative to thestraight portions, latitude skeletal elements approximately parallel tothe straight portions, and nodes of the both skeletal elements, meshesnot adjacent to the straight portion are surrounded by a pair ofapproximately parallel latitude skeletal elements, a pair ofapproximately parallel longitudinal skeletal elements, and a pair ofnodes opposing each other, meshes adjacent in latitudinal direction havethe longitudinal skeletal elements in common, the latitude skeletalelement has a length which is substantially not elongated from a stateof the sheet-shaped material, the longitudinal skeletal element has alength which is elongated from a state of the sheet-shaped materialwithin a range of breaking limit, and a lug is formed on one of thestraight portions by prolonging an end of that straight portion.

Since it is not necessary to leave the wide straight portion for formingthe lug in the lead acid storage battery plate having the abovestructure, an yield can be improved and it is possible to increase thisyield to 100% according to circumstances.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a grid for use in a lead acid storagebattery plate of embodiment 1.

FIG. 2 is a side view showing a die-set for use in a manufacturingmethod of an expanded mesh in the embodiment 1.

FIG. 3 is a sectional view taken on a line III--III of FIG. 2.

FIG. 4 is a sectional view taken on a line IV--IV of FIG. 2.

FIG. 5 is a partially enlarged side view showing a shearing cutter anddie of a die-set of FIG. 2.

FIG. 6 is a side view showing a state of manufacturing work of expandedmesh in the embodiment 1.

FIG. 7 is a sectional view taken on a line VII--VII of FIG. 6.

FIG. 8 is a partially enlarged side view showing a state where theshearing cutter is moved downward in the manufacturing work of expandedmesh in the embodiment 1.

FIG.9 is a partially enlarged side view showing a state where theshearing cutter is moved upward from the state of FIG. 8.

FIG. 10 is a partially enlarged side view for explaining a relationbetween a tooth of shearing cutter and a shape of mesh.

FIG. 11 is a front view showing a grid for use in a lead acid storagebattery plate of embodiment 2.

FIG. 12 is a front view showing a grid for use in a lead acid storagebattery plate of embodiment 3.

FIG. 13 is a partially enlarged side view showing a manufacturingprocess of expanded mesh in embodiment 4.

FIG. 14 is a partial front view showing an expanded mesh of embodiment5.

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1)

FIG. 1 is the front view showing the grid of the lead acid storagebattery plate using the expanded mesh of this invention. A grid 1 ismade up by cutting and working an expanded mesh 20 prepared as shown byFIG. 6 and FIG. 7 into prescribed shape and size. The grid 1 comprises alead alloy and is composed of a reticulated portion 2 and straightportions 3 & 4 comprising non-expanded portions formed on two-sides ofthe reticulated portion 2 opposing each other. The straight portions 3 &4 are in parallel each other. The one straight portion 3 is called as anupper rib and the other straight portion 4 is called as a lower rib. Theupper rib 3 functions as a current collector plate.

The reticulated portion 2 includes a large number of meshes 5 surroundedby longitudinal skeletal elements 51 inclining relative to the straightportions 3 & 4, latitude skeletal elements 52 approximately parallelwith the straight portions 3 & 4, and nodes 53 of the both skeletalelements 51 & 52. A mesh 5a adjacent to the straight portions 3 & 4 issurrounded by the longitudinal skeletal elements 51, the latitudeskeletal element 52, the nodes 53 and the straight portion 3 or 4. Themesh 5 is surrounded by a pair of approximately parallel longitudinalskeletal elements 51 & 51 and a pair of approximately parallel latitudeskeletal elements 52 & 52 and a pair of nodes 53 & 53 opposing eachother. The meshes 5 adjacent in latitudinal direction have thelongitudinal skeletal element 51 in common, and the meshes 5 adjacent inlongitudinal direction have the latitude skeletal element 52 in common.

In other words, each node 53 is divided at its both sides into thelongitudinal skeletal element 51 inclining relative to the straightportions 3 & 4 and the latitude skeletal element 52 approximatelyparallel to the straight portions 3 & 4, and the other ends ofrespective skeletal elements 51 & 52 connect to the nodes 53 located atrespective directions.

The grid 1 is of a sheet-shaped type made of a sheet-shaped material.The latitude skeletal element 52 has a length which is not elongatedfrom a state of the sheet-shaped material. The longitudinal skeletalelement 51 has a length which is elongated from the state of thesheet-shaped material within a range of breaking limit.

A lug 31 is so formed on the upper rib 3 unevenly as to be deviated toan elongated direction side of the longitudinal skeletal element 51.While, leg pieces 41 are formed on the lower rib 4.

Practical sizes of the grid 1 of this embodiment are 230 mm in height Hand 145 mm in width W of the reticulated portion 2, and 24 mm in pitch Sof the node 53. The meshes 5 & 5a are formed in 21 rows in a directionof height. The lead acid storage battery plate of this embodiment isdesigned for a stationary sealed-type lead acid storage battery, and thelead-calcium type alloy is used for the sheet-shaped material.

According to the grid 1 having the above structure, the grid 1 maintainsa flatness because the latitude skeletal element 52 has the length whichis not elongated from the state of the sheet-shaped material. Namely,the grid 1 is not bulged at its central part like a barrel.

When the grid 1 having the above structure is used for the lead acidstorage battery plate, the current collecting efficiency is made betterbecause the longitudinal skeletal elements 51 are directed to a positionwhere the lug 31 is located.

A method for manufacturing the expanded mesh 20 for use in the grid 1having the above structure will be explained hereunder.

FIG. 2 is the side view showing the die-set 6 used in this manufacturingmethod, FIG. 3 is the sectional view taken on the line III--III of FIG.2 and FIG. 4 is the sectional view taken on the line IV--IV of FIG. 2.In the die-set 6, an upper die base 61 is designed to be movedvertically by a drive mechanism (not shown) along a guide post 62 asshown by an arrow A. A cutter mounting bed 63 is fixed to the upper diebase 61, and shearing cutters 7 of same shapes and same sizes arearranged in one row and mounted on a lower face 63a of the mounting bed63. The lower face 63a is tilted by an angle α relative to a horizontalplane X i.e. a plane normal to the moving direction of the upper diebase 61. Namely, a line which connects spots corresponding to parts ofremaining sheet-shaped material between adjacent cutters 7 when shearingthe sheet-shaped material, is also tilted by the angle α relative to thehorizontal plane X. 64 is a sheet feed roller located at a feed originside of the sheet-shaped material. A die 66 having a shearing edge 66aopposing the cutter 7 and a feed face 66b feeding the sheet-shapedmaterial are secured to a lower die base 65. The shearing edge 66a faceson and in parallel with the lower face 63a. In other words, the shearingedge 66a is also tilted by the angle α relative to the horizontal planeX. The angle α is so tilted that the feed origin side is positionedlower and the feed destination side is positioned higher. The cutters 7are installed at 21 spots, and an installation pitch S of the cutters 7is set equal to a pitch S of the expanded mesh 1. The die 66 is cut atits other side from the shearing portion on the cutter 7 at feeddestination side end, so that a part forming the upper rib 3 can be bentand relieved.

As shown in FIG. 5, a tooth 71 of the shearing cutter 7 is formed into aconcave shape having a flat second tooth 71b at its top by a first tooth71a, the second tooth 71b and a third tooth 71c. The first tooth 71a istilted by an angle β relative to the horizontal plane X. The tooth 71has a symmetrical shape having the second tooth 71b at its center. Inthis embodiment, the α and β are 15 degrees and a width W1 of the secondtooth 71b is 3 mm.

The expanded mesh 20 is manufactured by using the die-set 6 having theabove structure in the following way. FIG. 6 is the side view showingthe state of midway of manufacture. FIG. 7 is the sectional view takenon the line VII--VII of FIG. 6. The sheet-shaped material 10 is passedthrough a roller 64 under a state of being inclined by an angle γ (FIG.7) relative to a row of the cutters 7 and sent to the shearing edge 66awith a prescribed pitch P. Under an intermittent stop condition infeeding, the upper die base 61 is moved vertically to cutbroken-line-like slits on the sheet-shaped material 10 and open theslits downward by the teeth 71 of the cutter 7. This work is carried outcontinuously. Thereby, the expanded mesh 20 having the meshes 5 arrangedat zigzag pattern is formed. In this operation, the material is fed tothe die-set 6 with one-side edge 10a of the sheet-shaped material 10located at a position of fully lower side in FIG. 7 from a feed originend cutter 7 and the other-side edge 10b located at a position of fullyupper side in FIG. 7 from a feed destination end cutter 7, so that theexpanded mesh 20 having the straight portions 3 & 4 comprising thenon-expanded portions can be obtained at both sides thereof. In thisinstance, the straight portion 4 is formed in a state of standingupright from a plane of the reticulated portion 2. However, the straightportion 4 can be taken out in flash with the plane of the reticulatedportion 2 by previously bending it or by installing a projection forbending at an outside of the feed origin end cutter 7. In case where theone-edge 10a of the sheet-shaped material 10 is scarcely protruded outof the feed origin side end cutter 7, it is not necessary to bend thestraight portion 4 for flattening. In FIG. 3, 67 is a sheet holdingmechanism.

FIG. 8 is the partially enlarged side view showing the state where thesheet is sheared by the cutter 7 into the broken-line-like shapes. FIG.9 is the partially enlarged side view showing the state where the cutter7 is raised after the shearing. FIG. 10 is the partially enlarged sideview for explaining the relation between the tooth of the cutter 7 andthe shape of the mesh 5. When the sheet-shaped material 10 is subjectedto the shearing work by the die-set 6 having the above structure, thelatitude skeletal element 52, is sheared and formed by the first tooth71a, becomes to have a length which is not elongated from the state ofthe sheet-shaped material 10 and the longitudinal skeletal element 51,is sheared and formed by the third tooth 71c, becomes to have a lengthwhich is elongated from the state of the sheet-shaped material 10 with aprescribed elongation ratio E, and the node 53 is formed of a part whichis located between teeth of adjoining cutters 7 and does not shear thesheet-shaped material 10. The detailed explanation is as follows. Asillustrated in FIG. 10; the inclining angle of the first tooth 71arelative to the horizontal plane X or a plane normal to the movingdirection of the cutter 7 is β, the inclining angle of the entire cuter7 relative to the horizontal plane X is α, and the inclining angle ofthe die 66 or the sheet-shaped material 10 relative to the horizontalplane X is α. Therefore, in a part of the sheet-shaped material 10immediately after being sheared by the cutter 7, a triangle having sidesa and b becomes an isosceles triangle because α is equal to β. Namely, alength of the side a is equal to a length of the side b. Consequently,the sheet-shaped material 10 is sheared downward with its length as itis so that the latitude skeletal element 52 becomes to have a lengthwhich is not elongated from the state of the sheet-shaped material 10.On the other hand, the side d or the longitudinal skeletal element 51has a length which is elongated from the side c at a prescribedelongation ratio E as illustrated in FIG. 10. Incidentally, thesheet-shaped material 10 has a breaking limit at which it is broken whenelongated beyond the limit. The elongation ratio E of the longitudinalskeletal element 51 must naturally be within a range of the breakinglimit. The elongation ratio E can be calculated from the followingequation. ##EQU1## where δ=α+β because the cutter 7 has a symmetricalshape with its center at the second tooth 71b. Therefore, the aboveequation becomes as follows. Elongation ratio E=cos α/cos (2α+β)

Since α=β=15 degrees in this embodiment, the elongation percentage E isequal to 1.366. A breaking limit of the lead-calcium alloy forming thesheet-shaped material 10 is about 1.4. Accordingly, the longitudinalskeletal element 51 can be formed without being broken in thisembodiment.

A cut width W2 (not shown) of the sheet-shaped material 10 i.e. a widthof the longitudinal skeletal element 51 and the latitude skeletalelement 52 before being subjected to elongation, can be expressed by thefollowing equation.

    W2=P·sinγ·cosα

While, in order to form the meshes 5 of the reticulated portion 2 intothe zigzag shape as illustrated by the figure, it is necessary to set avalue of the pitch P close to a value of a width W3 (FIG. 5) up to acentral part of the second tooth 71b of the cutter 7. The W3 is equal to12 mm and the angle γ is equal to 6 degrees in this embodiment, so thatsin γ·cos α is about 0.1. Therefore, the cut width W2 becomes 1.1 mmwhen the pitch P is 11 mm, and the cut width W2 becomes 1.4 mm when thepitch P is 14 mm.

As mentioned above, according to the above manufacturing method usingthe die-set 6 having the above structure, the following effects can beobtained.

(1) The expanded mesh 20 having at least any one of the straightportions 3 & 4 can be formed continuously from the sheet-shaped material10.

(2) The latitude skeletal elements 52 composing the meshes 5 can beformed as one having the length which is not elongated from the state ofthe sheet-shaped material 10. Consequently, the expanded mesh 20 in thestate not bulged like a drum i.e. in the flat state can be obtained.

(3) Since the work making cut-slits is done simultaneously with theopening work, a precision of the reticulated portion can be improved.Since a special opening process is not required, the work can besimplified. When a device for shifting phases of the straight portions 3& 4 at both sides is installed additionally in the next process, adegree of opening of mesh can be changed.

(4) By only changing the feed angle or the feed pitch of thesheet-shaped material 10 to the die-set 6, the reticulated portions 2with different cut widths can be formed easily by the same die-set 6.

(5) By only changing the number of cutter 7 used, a height(corresponding to H of FIG. 1) of the reticulated portion 2 can bechanged easily.

(6) Since the mounting face 63b of the cutter 7 of the mounting bed 63is flat, the cutters 7 arranged in one row can be made up integrallyfrom a flat plate and the pitch of the cutters 7 can thereby be setfreely without making bones about relation with fitting holes.Therefore, the cutters 7 can be replaced easily and it becomes easy tocope with a change in shape of the mesh.

(7) Cutters 7 having same shapes and same sizes may be used even at thefeed origin side end and feed destination side end. Consequently, themeshes 5a in the vicinity of the straight portions 3 & 4 comprising thenon-expanded portions can be formed in about same sizes as the othermeshes S. Namely, it is not necessary to minimize the sizes of meshes inthe vicinity of the non-expanded portions as required in conventionalcases. Accordingly, the sheet-shaped material 10 can be utilizedeffectively and the expanded mesh able to hold much more activematerials can be obtained.

(8) Since the straight portions 3 & 4 are arranged in parallel with adirection of manufacture of the expanded mesh 20, pasting process ofpaste-like active material can be carried out continuously onto theexpanded mesh having the straight portions comprising the non-expandedportions.

(9) In the die-set 6 having the above structure, the straight portion 3obtained in FIG. 7 can be relieved while being bent and the reticulatedportion 2 can be prevented from being deformed because the die 66 doesnot exist at a further feed destination side from the cutter 7 locatedat the feed destination side end. When the die 66 at a further feeddestination side from the cutter 7 located at the feed destination sideend is so formed into an circular shape as to be relieved, it becomespossible to eliminate an indentation made on a backside of the straightportion 3.

(10) In the die-set 6 having the above structure, the die 66 is cut at afurther feed destination side from the cutter 7 located at the feeddestination side end. When this cutting line is made deeper as it getsto the backside as shown by 66c of FIG. 4, the obtained reticulatedportion 2 can be drawn out on the gentle slope.

(11) When the pitch P is made small as compared with the width W3 (FIG.5) of the first cutter 7 or a push-in depth of the cutter 7 into thesheet-shaped material 10 is made large as compared with the case of FIG.8, corrugations in a direction of thickness of sheet-shaped material 10are scarcely formed on the straight portions comprising the non-expandedportions. Slight corrugations may be flattened by roller work etc. in anafter-process.

(12) Even if lengths of the row of cutter 7 and the shearing edge 66a ofthe die 66 are short as compared with lengths of the conventionalparallel cutter system, an expanded mesh satisfied in its height (H ofFIG. 1) can be obtained. Namely, a desired expanded mesh can be obtainedby a small die-set. In concrete, as an example of aforesaid lead-calciumalloy, a length of the row of cutter 7 of the die-set 6 for obtaining anexpanded mesh with a height H of 230 mm, corresponds to 24 (mm) by 21(teeth) which is about 500 mm. On the contrary, when an opening heightof one cutter is assumed as 7.8 mm, a required length of cutter rowbecomes 24 mm×1.5×(230 mm/7.8 mm)=1,080 mm in the parallel cuttersystem. A press machine driving such a long cutter row is extremelyparticular one which is slow in its drive speed and can not manufacturethe expanded mesh with low cost and at high speed. Only an expanded meshwith a height of about 150 mm can be obtained in the conventionalparallel cutter system, on the condition that the length of cutter rowshould be kept within 700 mm which is a limit length in order not to usea particular press machine. In other words, the above-mentionedmanufacturing method of this invention can be applied effectively forobtaining an expanded mesh of lead acid storage battery plate having aheight of about 150 mm or larger.

(13) Since the lug 31 which is deviated to the elongation direction sideof the longitudinal skeletal element 51, is made on the upper rib 3, acurrent collecting efficiency can be improved when the expanded mesh isapplied to the lead acid storage battery plate. Since a direction of thefixed lug 31 coincides with the elongation direction of the positiveplate, the elongation of positive plate can be prevented when theexpanded mesh is applied to the positive plate of lead acid storagebattery.

A lead acid storage battery plate can be prepared from the expanded meshobtained through the above manufacturing method, by being subjected tothe following processes [1] to [4].

[1] Flattening process, in which concave parts of the reticulatedportions 2 are crushed down and bendings of the straight portions 3 & 4relative to the reticulated portion 2 are removed, so that the entireexpanded mesh is flattened.

[2] Pasting process, in which a pasting paper is made contact with abackside of the mesh and a paste-like active material is appliedthereon, and the pasting paper is made contact with a front side of themesh and pressed thereon.

[3] Trimming process, in which a lug 31 and a leg piece 41 are punchedand formed from the straight portions 3 & 4 at both sides of thereticulated portion 2, so that the mesh is cut to a plate size.

[4] Drying process, in which the plate is dried.

(Embodiment 2)

FIG. 11 is the front view showing the grid for use in the lead acidstorage battery plate of this invention. This grid 1a is formed in sucha way that an expanded mesh 20 prepared as shown in FIG. 6 and FIG. 7 byusing a sheet-shaped material comprising a copper alloy is cut toprescribed size and shape, a current collector plate 80 made of leadalloy having a lug 81 is attached thereto, a surface of the reticulatedportion 2 is thereafter subjected to lead coating treatment, and asupport plate 90 made of resin having a leg piece 91 is attachedthereto. In other words, the grid 1a has a structure in which theexpanded mesh of embodiment 1 is turned by 90 degrees, and thereticulated portion 2 has a large number of meshes 5 surrounded bylongitudinal skeletal elements 51 inclined relative to the straightportions 3 & 4, latitude skeletal elements 52 approximately parallel tothe straight portions 3 & 4, and nodes 53 of the both skeletal elements51 & 52. The current collector plate 80 is attached thereto by castingand the support plate 90 is attached thereto by bonding. When thepaste-like active material is applied to the grid 1a, the lead acidstorage battery plate is prepared.

In the grid 1a having the above structure, the mesh 5 is prevented fromopening to both right and left sides by the straight portions 3 & 4.Therefore, the paste-like active material applied to this part can beprevented from falling off so that a holding rate of the paste-likeactive material can be improved as compared with the grid 1 ofembodiment 1.

(Embodiment 3)

FIG. 12 is the front view showing the grid for use in the lead acidstorage battery plate of this invention. This grid 1b is manufactured inthe same manufacturing method as that of the lead acid storage batteryplate shown in the embodiment 1. However, its trimming process isdifferent from a trimming process of embodiment 1 in a point that thestraight portion 3 is punched into a shape as shown in the figure. Thegrid 1b has a structure in which the expanded mesh of embodiment 1 isturned by 90 degrees in the same way as the grid 1a of embodiment 2, andthe reticulated portion 2 has a large number of meshes 5 surrounded bylongitudinal skeletal elements 51 inclined relative to the straightportions 3 & 4, latitude skeletal elements 52 approximately parallel tothe straight portions 3 & 4, and nodes 53 of the both skeletal elements51 & 52.

A lug 31 is made on one end of the straight portion 3 into a shape ofits extension and the other end of it is notched. The notched portion ofthe other end is a portion becoming a lug of a succeeding grid. In amanufacture of the grid 1b of this embodiment, a cutter 7 having nosecond tooth 71b or a tip pointed cutter 7 is used.

In the grid 1b having the above structure, it is not necessary to leavethe straight portion having a large width for forming the lug, so that ayield can be improved and a yield of 100% may be accomplished ifcircumstances require.

(Embodiment 4)

FIG. 13 is the partially enlarged side view showing one manufacturingprocess partially using a different shaped cutter 7a in the die-set 6.The cutter 7a has a size larger than those of other cutters 7. In thiscase, an expanded mesh partially including meshes 5b having large sizesformed by the cutter 7a can be prepared.

(Embodiment 5)

FIG. 14 is the partial front view showing the expanded mesh 20, in whichthe node is overlapping with the latitude skeletal element 52, and thelatitude skeletal element 52 has a thickness twice as large as that ofthe longitudinal skeletal element 51 before being cut open. The latitudeskeletal element 52 has a length which is not elongated from a length ofthe sheet-shaped material.

This expanded mesh 20b is prepared in such a way that a cut length ofthe cutter 7 in the die-set 6 is made similar to a non-cut lengthbetween it and an adjacent cutter 7, and the pitch P is made about twothirds of the width W3 (FIG. 5) of the cutter 7. Namely, the expandedmesh 20b having a shape wherein the node is apparently overlapping withthe latitude skeletal element 52, can be formed.

(Other Embodiments)

Following structures may be used.

(1) A die having a structure in which shearing portions facing eachother are formed at both sides and distances between the both shearingportions are gradually increasing, from upside to downside, that is,from the feed destination side to the feed origin side, may be used incombination with a cutter row arranged in two lines in correspondencewith the shearing portions. According to this structure, an expandedmesh having a non-expanded straight portion at its intermediate part canbe obtained.

(2) A structure may be used in which an intermediate part of the die iseliminated to be formed into a stepped shape i.e. an intermediate dieand cutters are eliminated so as to shorten them. Even by thisstructure, an expanded mesh having the non-expanded straight portion atits intermediate part can be obtained.

(3) By using a cutter having unsymmetrical left and right teeth, lengthsand angles of the longitudinal skeletal element and latitude skeletalelement of the obtained expanded mesh can be changed.

(4) A cutter having a tooth comprising the first tooth and the thirdtooth only, i.e. a cutter having a tip pointed tooth, may be used. Whenthe node is located at a position in line with the longitudinal skeletalelement or latitude skeletal element in this case, the tip pointed partof the tooth does not touch with the node so that the expanded mesh canbe manufactured without giving an excessive force to it.

(5) A cutter may be used, in which at least one of the first tooth andthe third tooth has a curved face.

(6) A cutter having a small tooth height may be used for a feed originside end cutter or a feed destination side end cutter, among cuttersarranged in one row. According to this structure, an elongationpercentage of a longitudinal skeletal element located at a boundary withthe straight portion comprising the non-expanded portion can beminimized so as to control a breakage of the longitudinal skeletalelement.

(7) In case for example where a longitudinal skeletal element formed inthe vicinity of the feed destination side end is required to be madethick, it is enough to further tilt a flat-viewed angle of shearingedges of the cutter and die at that part relative to the sheet-shapedmaterial.

(8) In case for example where an elongation percentage of a longitudinalskeletal element formed in the vicinity of the feed destination side endis required to be minimized, it is enough to decrease an angle ofshearing edges of the cutter and die at that part relative to thehorizontal plane.

(9) In the die-set 6, the upper die 61 moves vertically and the cutter 7and the shearing edge 66a incline relative to the horizontal plane bythe angle α. However, the angular relation between the two is relative.Therefore, a die-set may be manufactured and used, in which the cutterand the shearing edge are in horizontal positions and the upper diemoves in a position tilted by the angle α.

(10) Each cutter may be so installed that it can swing around a swingcenter located at the feed origin side and the relative angular relationmentioned in the above paragraph (9) is maintained.

(11) The straight portion comprising the non-expanded portion formed onthe feed origin side is apt to be bent relative to a plane comprisingthe reticulated portion. To cope with this problem, a pre-bendingopposite to the above bent side is worked on a part of the sheet-shapedmaterial which will become the above straight portion. The bending ofthe straight portion can thereby be controlled so as to ease theflattening work after that.

Industrial Applicability

The expanded mesh of this invention is flat because its latitudeskeletal element has a length which is not elongated from a state ofsheet-shaped material, and straight portions can be formed on opposingtwo sides. Therefore, the expanded mesh can be utilized effectively invarious fields, and particularly can be utilized effectively for a gridof lead acid storage battery plate.

What is claimed is:
 1. A manufacturing method of sheet-shaped expandedmesh made of a sheet-shaped material; characterized in thatthe expandedmesh comprises a reticulated portion and straight portions composed ofnon-expanded portions formed at least on one-side, the reticulatedportion has a large number of meshes surrounded by longitudinal skeletalelements inclining relative to the straight portions, latitude skeletalelements approximately parallel to the straight portions, and nodes ofthe both skeletal elements, meshes not adjacent to the straight portionsare surrounded by a pair of approximately parallel latitude skeletalelements, a pair of approximately parallel longitudinal skeletalelements, and a pair of nodes opposing each other, meshes adjacent inlatitudinal direction have the longitudinal skeletal elements in common,a die-set is used which is equipped with at least one-row of dieinstalled in an inclining position relative to a feed direction of thesheet-shaped material and plural shearing cutters protruding at itsmiddle part and shearing with the die to shear the sheet-shaped materialinto broken-line-like shapes and opening it to form the reticulatedportion, and a direction of shearing motion relative to the die ofshearing cutter is set in a direction inclining to a thickness directionof the sheet-shaped material so as to include a pitch feed motion of thesheet-shaped material from its feed destination side to its feed originside.
 2. A manufacturing method of sheet-shaped expanded mesh as setforth in claim 1, in which the shearing cutter has at its tip end atooth protruding at its central part;the tooth has at least a firsttooth for shearing and forming the latitude skeletal element and a thirdtooth for shearing and forming the longitudinal skeletal element; thefirst tooth is inclined by a first angle relative to a plane normal tothe direction of shearing motion of the cutter, the sheet-shapedmaterial facing on the cutter is inclined by a second angle to a sideopposite to the first tooth relative to a plane normal to the directionof shearing motion of the cutter, and the first angle is set to a valueapproximately equal to or smaller than the second angle, the node isformed of a part, which is located between teeth of adjoining cuttersand does not shear the sheet-shaped material, by pitch feeding thesheet-shaped material at a pitch smaller than or equal to a tooth widthof the cutter.